Seeing GroEL at 6 A resolution by single particle electron cryomicroscopy

Structure. 2004 Jul;12(7):1129-36. doi: 10.1016/j.str.2004.05.006.


We present a reconstruction of native GroEL by electron cryomicroscopy (cryo-EM) and single particle analysis at 6 A resolution. alpha helices are clearly visible and beta sheet density is also visible at this resolution. While the overall conformation of this structure is quite consistent with the published X-ray data, a measurable shift in the positions of three alpha helices in the intermediate domain is observed, not consistent with any of the 7 monomeric structures in the Protein Data Bank model (1OEL). In addition, there is evidence for slight rearrangement or flexibility in parts of the apical domain. The 6 A resolution cryo-EM GroEL structure clearly demonstrates the veracity and expanding scope of cryo-EM and the single particle reconstruction technique for macromolecular machines.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Chaperonin 60 / chemistry*
  • Cryoelectron Microscopy / methods*
  • Crystallography, X-Ray
  • Protein Structure, Quaternary
  • Protein Structure, Secondary


  • Chaperonin 60